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Communication and YOU

Communication and YOU

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Discussion: Communication and YOU

Nonverbal communication helps us to express who we really are. Our identities, which include our cultures, our interests and hobbies, and the groups we belong to, are conveyed verbally by utilizing how we establish our working and living spaces (proxemics), our voices, tones and accents, our clothes, and how we carry ourselves. However, some nonverbal behaviors, such as height, are not under our control (Burgoon et al., 2021). People get an impression concerning who we are from our physical bodies. Nevertheless, we have substantial control over several nonverbal communication aspects concerning how people communicate their identities.

Sometimes I ask myself whether I am conveying the image I desire. Considering the projection of my desired image, my level of attractiveness conveys the image I desire because I get multiple credits on the same. Also, I have the height I desire. I did not wish to be very tall or very short. My medium height contributes to positive proxemics, which results in many comfortable close associations with friends.

Additionally, every person I come across comments about my eye contact usually. I do not shy away, and like the image, I project as it is my desire. However, I sometimes feel I do not convey the image I desire. For instance, some people fail to interpret the meanings of my kinesics, such as facial expressions and body movements. Some may view my firm eye contact as disrespectful.

I think I can present and carry myself through eye contact, haptics, kinesics, tone of voice, and posture alteration to my advantage. For example, by altering these nonverbal cues, I can present myself as distant or warm as per the context (Morgan et al., 2017). Also, I can pay substantial attention to what the other person is saying to become a helpful listener. In addition, I think I can maintain comfortable eye contact by avoiding staring.

In conclusion, nonverbal communication is significant in expressing our identities. People have much control over several nonverbal communication aspects related to how people communicate their identities. I usually convey my desired image through my attractiveness, eye contact, and medium height. I think I can present and carry myself through nonverbal cues such as eye contact and posture alteration to my advantage. Therefore, I will ensure presenting myself using various nonverbal cues alterations to employ skills that will advantage me in communicating effectively.

References

Burgoon, J. K., Manusov, V., & Guerrero, L. K. (2021). Nonverbal communication. Routledge.

Morgan, S. E., Occa, A., Mouton, A., & Potter, J. (2017). The role of nonverbal communication behaviors in clinical trial and research study recruitment. Health Communication, 32(4), 461-469.

Vitamin D Deficiency Prevalence in Industrialized Countries

Vitamin D Deficiency Prevalence in Industrialized Countries

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Abstract

Vitamin D deficiency in the body, especially subclinical vitamin D deficiency, is common in both developed and developing nations. However, the deficiency is prevalent in developed countries for various reasons. This deficiency affects approximately 5% of the United States population. Despite the U.S not being the country with the most deficiency cases, it still records high cases of deficiencies annually. It is quite saddening that these cases continue to rise by day despite all the efforts employed by the government to put vitamin D deficiency under control with the hope of eliminating it from society. Last year alone, the country recorded 30% cases of the deficiency, 80% of which involved children below twelve years. Research shows that one out of five men and one out of nine women suffer have been affected by vitamin D deficiency. This statistic is the highest the country has recorded in ten years since the county established and implemented strict measures to curb its spread in the population, especially among children. Health experts in America consider vitamin D deficiency as a historically significant disease. This project evaluates the prevalence of vitamin C deficiency in America, the affected population, and the measures in place to deal with the issue.

Introduction

Over time there have been debates at the national level regarding Vitamin D deficiency, whether or not to categorize it as chronic by the government through the healthcare department. Many healthcare practitioners have discovered a strong correlation between high vitamin D deficiency levels and the unhealthy lifestyles of older people in America. Recently Americans have embraced an unhealthy lifestyle that constitutes lousy eating habits, little attention to vitamins and vegetables in a diet, lack of exposure to enough sunlight, and most importantly, ignoring exercises and their significance in strengthening bones and improving one’s health. The most affected individuals in developed nations are children below ten years, particularly children from low-income backgrounds. It is the case because children are vulnerable and still growing, thus requiring attention and a good diet. Their bones are still weak and prone to illnesses if they lack enough vitamins in their foods. This paper will discuss the prevalence of vitamin D deficiency in America, its implications, and the appropriate measures to eliminate the issue in the country.

Background

Understanding vitamin D, its importance, and the causes of Vitamin D deficiency give a better understanding of its prevalence in developed countries like America. Vitamin D deficiency, also known as Hypovitaminosis D, means that an individual is not getting enough vitamin D nutrients in their body to sustain them and keep them healthy. The hormonally active vitamin D3 is a lipid-soluble compound known as 1,25-dihydroxy vitamin D3 (cholecalciferol). The lipid-soluble vitamin is significant because it affects bone metabolism and calcium homeostasis. Vitamin D is essential for the body because it helps it absorb calcium easily from food. It also plays a vital role in strengthening individuals’ muscle, nervous, and immune systems. Vitamin D can be acquired into the body in three significant ways. The most common form is through the skin, followed by diet, and finally through supplements. Absorption of vitamin D through the skin is common because it only requires exposure to sunlight daily. The human body is unique because it has mechanisms and the ability to form Vitamin D naturally after exposure to sunlight. The risk of developing damaged skin, aging skin, and cancer through excessive sunlight have seen many people in America acquire vitamin D and ultimately prevent vitamin D deficiency through other methods like dietary and supplements.

The need for vitamin D in the body to free an individual from the risk of vitamin D deficiency varies depending on age. People at high risk of Vitamin D deficiency need more vitamin D in their bloodstream. Since children are prone to vitamin D deficiency, they require approximately 600 IU. The same goes for young adults pregnant and breastfeeding mothers. Adults over 71 years old require more vitamin D because their bones are very fragile and require a constant dose of vitamin D. They need approximately 800 IU to get off the radar of vitamin D deficiency. Several groups of people in developed countries are at risk of getting vitamin D deficiency. Infants are the most vulnerable because they depend on breastmilk as their source of nutrients. According to Hassan-Smith and colleagues, breastmilk is a poor source of Vitamins prompting most parents to top it up with supplements. Individuals taking anti-seizure, anti-fungal, glucocorticoids, HIV/AIDS, and cholestyramine drugs are known to slow vitamin D mechanisms are also at high risk of getting vitamin D deficiency.

Data collected by the National Health and Nutrition Examination Survey (NHANES) between the years 2005-2008 established that out of 4495-individual sample size, 41.6% registered levels of vitamin D deficiency. The research also determined that race was a key factor in the deficiency for two fundamental reasons. One is because skin pigmentation reduces the absorption and synthesis of vitamin D. Vitamin D is a vital hormone synthesized by the skin and is responsible for pigmentation. The synthesis is highly dependent on melanin concentration on the skin. Generally, melanin is known to scatter and distribute the ultra-violet rays harvested from the sunlight, causing inefficient conversion of 7-dehydrocholesterol to pre-vitamin D3. Therefore, this aspect means that people with the darkest melanin experience slower vitamin D synthesis than light-skinned individuals. Studies have suggested a positive correlation between skin lightness and 25-hydroxyvitamin D (25(O.H.) D) levels. Research by Vitamin D External Quality Assessment Scheme Organization DEQAS states that fair-skinned children in developed countries recorded high pigmentation values meaning their levels of 25(O.H.) D component is high in their skin. It explains why African Americans and Hispanics struggle to get vitamin D into their bodies and counter the deficiency.

Current Research Efforts

Most cases of vitamin D recorded emerged from the African American community, particularly the adults. Followed closely by the Hispanic adults. Research shows that these two groups are prevalent to vitamin D deficiency because of the demographic and economic disadvantage they have as marginalized groups in America. It is quite challenging for African Americans and the Hispanic group to secure suitable employment because of their skin color and the stereotypical nature of society. For this reason, they struggle to offset their finances, tax payments, and their needs, including a healthy meal. The consumption of foods with vitamin D nutrients and supplements proves difficult for these groups because of the affordability factor. Consequently, calcium absorption in their bodies is limited hence developing vitamin D deficiency over time.

Vitamin D deficiency can result in bone density loss, a factor that contributes to fractures or broken bones and osteoporosis. In children, severe vitamin D deficiency can lead to rickets. Rickets is a rare disease that affects young children and comes about due to inadequate vitamin D, which makes it difficult for them to absorb calcium and phosphorus. Rickets causes the bones of children to soften and weaken hence bending the legs and making a bow shape. Rickets also causes pain in the pelvis, spine, and legs. Nutritional rickets has been reported from at least 59 developed countries in the past twenty years. A study revealed that in North America, rickets as a result of vitamin D deficiency is common among children with relatively pigmented skin because they are exclusively breastfed. In countries like Australia, vitamin D deficiency is prevalent in immigrant populations. Most of these immigrants originate from the Indian and Middle East countries. Studies further show that rickets and vitamin D deficiencies reported in developed continents like Europe are common among children whose mothers lack adequate calcium in their bodies or are sun-protected. This deficiency can manifest later in adulthood as bone problems. The manifestation of vitamin D deficiency in extreme cases like rickets occurs mainly in children’s second and third years.

A study facilitated by National Health and Nutrition Examination Survey (NHANES) in Europe shows that vitamin D deficiency burdens specific populations in the country. It contributes massively to the downstream clinical reverberations ranging from cancer, osteoporosis, heart diseases, diabetes, clinical features to fractures and kidney problems. The populations affected mainly by vitamin D deficiency find it challenging to access foods rich in vitamin D. Researchers have demonstrated that populations prone to vitamin D deficiency like the Latinos and black Americans get their vitamin D mainly from exposure to ultraviolet rays in sunlight. It provides the lipid-soluble compound of vitamin D3 and maintains the synthesis of nonenzymatic dermal in the body. According to the Vitamin D Standardization-Certification Program (VDSCP), sources of vitamin D2 such as fungal and dietary plants such as mushrooms that boost calcium absorption in the body are quite expensive in developed nations. Other alternative vitamin D3 sources like animal products, particularly fatty fish, are too costly for the marginalized groups in America to afford. These statistics explain why they are more prone to getting vitamin D deficiency.

Discussion

The changes in patterns and prevalence of vitamin D deficiency in developed countries have gained the interest of many medical researchers and practitioners. Anthropometric, demographic, and lifestyle factors predict vitamin D deficiency, rickets, and bone problems among adults worldwide. According to the Vitamin and Mineral Nutrition Information System (VMNIS), vitamin D status deteriorates over seventy years. The main factors contributing to the difficulty in acquiring and synthesizing vitamin D during old age are the little exposure to the ultra-UV rays from sunlight due to limited movements and cutaneous synthesis. Cutaneous synthesis of vitamin D in an individual’s body also depends on the clothes they choose to put on and sunscreens used to protect the skin from harmful U.V. rays from the sun. RESEARCH under controlled conditions revealed that sunscreens hinder the synthesis and absorption of vitamin D and the ultimate extraction of calcium and phosphorus from the vitamin D into the body. The Centers for Disease Control and Prevention and Nutrition International (N.I.) counter these arguments by suggesting that the regular use of sunscreens to protect the skin causes little to no damage because it does not impair the vitamin D production and synthesis process. The different points of view surrounding the screen raise a dilemma and debate on public health’s importance and effects of the product. Despite the solar radiations making up the primary vitamin D source, they are a risk factor for skin carcinogenesis and sunburns. Balancing the limit to skin damaged by sun radiations and generating adequate vitamin D to strengthen bones, muscle, and immune systems have created controversies among medical researchers worldwide.

The presence and amalgamation of vitamin D in the body also declines in patience with hip fractures. According to a 2019 report by the U.S. Department of Health and Human Services, 57.5% of elderly individuals with hip fractures in America have vitamin D deficiency, while 34.5% have vitamin D inefficiency. The health department adds that only 8% of people with hip fractures in America are free of vitamin D deficiency. A large percentage of vitamin D deficiency cases reported come from elderly female patients in America. The Comanaged Geriatric Fracture Centres record similar statistics as the low inpatient mortality regarding patients with hip fractures which stands at 1.95%. Studies have also suggested that cases of community-ambulant elderly patients with hip fractures are lower than state-bound cases. Housebound elderly patients are likely to get vitamin D deficiency because they do not expose themselves to enough sunlight. Lack of adequate sunlight means they don’t get ultra-violet rays from the sun, which is vital for synthesizing vitamin D and calcium absorption, responsible for strengthening bones.

Additionally, housebound elderly patients with hip fractures who have reduced physical activity are confined indoors for most of their lives. Lack of regular exercise makes their immune system weak, and they become vulnerable hence quickly succumbing to diseases that can cost their lives. Data collected by the National Health and Nutrition Examination Survey (NHANES) identifies other risk factors likely to increase the chances of inbound elderly patients with hip fractures getting vitamin D deficiency. These factors include coexisting illnesses such as renal and liver impairment and inadequate vitamin D dietary sources of vitamin D. Before admission to inbound states, statistics show that elderly patients with hip fractures residing in their homes and nursing homes did not have direct cases linked to vitamin D deficiency. However, a Turkish study conducted in 2019 revealed that patients living in nursing homes were at a higher risk of getting vitamin D deficiency compared to those living in their homes. It implies that the elderly living in their homes are well taken care of by their assistants or loved ones. They get balanced and enough meals every day, which boosts vitamin D levels in their bodies and eases conversion and absorption of vitamin D. Furthermore, they also get to go for regular walks that are not necessarily scheduled because of the personalized care. This aspect increases their exposure to sunlight and the acquisition of vitamin D through their skin.

Research by the United States Library of Medicine and National Institute of Health (2020) also found a strong correlation between the clothing habits of people in developed countries and higher risks of vitamin D deficiencies. Younger individuals with less pigmented skin tend to have balanced calcium, phosphate, and bone structure than fair-skinned adults or the elderly, thanks to their quick metabolism and vitamin D synthesis. Therefore, the elderly must increase their exposure time to sunlight twice as much or more to get the same level of vitamin D synthesis and protect themselves from vitamin D deficiency. Research in the United Kingdom and France has determined a relationship between latitude and the general vitamin D status in society. The Spanish Costa del Sol, which corresponds to a latitude of 37 degrees Celsius, recorded low vitamin D3 production in the residents’ bodies during winter. During winter, individuals put on heavy clothes covering most parts of their bodies. This aspect and little sunshine during this season contribute to lower levels of vitamin D deficiency in individuals living in developed nations.

Vitamin D deficiency prevalence also depends on the lifestyle of individuals in developed countries. Studies show that countries like Saudi Arabia, which is in the Middle East, recorded high cases of vitamin D deficiencies because of their clothing habits. Their culture dictates that they cover most parts of their bodies, especially in social settings. The study further revealed that women depicted more vitamin D deficiency signs than their male counterparts, thanks to their dressing habits. Countries with the lowest 25(O.H.) D levels recorded high vitamin D deficiency cases, especially in veiled women. Undoubtedly clothing limits their access and exposure to sunlight containing the U.V. rays responsible for the synthesis of Vitamin D. Other studies in Europe show that vitamin D deficiency is common among people living near the equator. Over the years, the prevalence of the deficiency has intensified around these areas. Researchers based in fourteen European countries applied Vitamin D Standardized Program (VDSP) protocol in their research and determined that 13.0% of the population displayed a low concentration of the serum 25-hydroxyvitamin D (25OHD. This statistic translates to approximately 55,844 people living around the equator. The results mean that the vitamin D concentration in the blood is below average, which is 30 nmol/l regardless of clothing habits, ethnic background, and age group.

Studies have established that 15-30 minutes exposure of hands and face to enough sunlight wavelength (UVB radiation of 290–370 nm) at around eleven to one P.M is enough to achieve a standard vitamin D concentration in the body. There are sufficient UVB radiations responsible for Vitamin D production in regions with a latitude of forty degrees south and 40 degrees north. Routine tests of vitamin D concentration (25OHD have not been conducted in sunny developed countries because of the assumption that vitamin D deficiency is not a severe issue. The health departments of developed sunny countries ignore vitamin D deficiency because they believe there is enough sunlight as a source of vitamin D. However, it should be noted that vitamin D deficiency might be higher in such countries due to ignorance. The sun might be the primary source of Vitamin D, but it is not the only source. There are other sources like dietary and supplements that need consideration. Researchers have suggested that UVB radiations are inadequate and sometimes not present during winter in countries outside the latitudes of forty degrees North and South. Therefore, people living in such reasons are forced to substitute their vitamin D source with supplementation and food. They rely on these sources to balance the serum vitamin D in their bodies as a measure against getting vitamin D deficiency. It is undeniable that geographical location plays a vital role in determining vitamin D deficiency. The ignorance of routine checks for Vitamin D deficiency in sunny areas raises questions and debates among different groups of people and heads worldwide and the course of action.

Vitamin D Deficiency and Osteomalacia

Osteomalacia is a bone disease that softens the bones and makes them weak in adults, eventually leading to the bowing of the weight-bearing bones of the legs during growth. This disease comes about due to the inadequacy of phosphorus or calcium that results in defective mineralization. Severe vitamin D deficiency causes Osteomalacia disease because it facilitates excessive calcium resorption from bone. This disease is closely associated with rickets in children since it has the same effect on the patients. Studies in Australia have determined that osteoporosis and falls and their subsequent fractures risks are the leading cause of vitamin D deficiency in the musculoskeletal health in adults living in industrialized countries. These conditions contribute massively to high healthcare costs and morbidity in developed countries. The National Health and Nutrition Examination Survey (NHANES) suggests that despite the prevalence of vitamin D deficiency in developed countries, osteoporosis and falls conditions are not suitable determinants of vitamin D status in the population. The institution adds that intervention to vitamin D deficiency in people of developed countries such as fortification and supplementation should not be based on these two conditions because they do not accurately represent vitamin status.

Vitamin D deficiency and Tuberculosis Asthma and Acute respiratory infections

Studies have revealed substantial evidence linking vitamin D deficiency with the development of respiratory difficulties, specifically the reactivation of tuberculosis and aggravation of asthmatic attacks. The inadequacy of Vitamin D in an individual’s body impacts the balance of their immune system adversely, weakening the body and making it vulnerable to illnesses like tuberculosis and asthma. A recent study stated that a consistent intake of vitamin D supplements increases one’s immunity and decreases the frequency of asthma and other Upper Respiratory Infections. The research also determined that Acute Respiratory Infections are common for children under the age of five in both developed and developing countries. Approximately 300 people worldwide are asthmatic. Out of this figure, 250 000 people succumb to death annually thanks to asthma, particularly acute asthma attacks. It is safe to conclude that enough vitamin D concentration in the body eases the disease burden on people residing in countries with high economies.

The supplementation trials conducted by Parva and colleagues revealed that vitamin D supplements were responsible for a significant decrease of severe asthma episodes requiring urgent medical attention and a decrease in the asthma aggravation frequencies requiring the corticosteroid treatment. Two trials facilitated by the authors involving maternal prenatal vitamin D supplementation showed a significant decline in the offspring recurrent incidences of asthmatic attacks. Additionally, research shows that vitamin D plays a vital role in preventing Mycobacterium tuberculosis infections in adults living in industrialized countries. Vitamin D concentration in the body is used as concomitant therapy to improve response to antimicrobial treatment and prevent active tuberculosis. Vitamin D deficiency, therefore, leaves the body vulnerable to life-threatening conditions and ultimate loss of life if not adequately addressed.

Recommendations

The high prevalence of vitamin D deficiency has prompted the governments of many industrialized countries to develop strategies and measures to tackle the adverse impacts of the deficiency on the population and the ultimate prevention against it. Efforts have been established to cover all vitamin D sources but focus primarily on food as a dietary source. Various foods programs are already in motion to tackle the issue and reduce the burden of vitamin D deficiency on the population. In addition, the government and stakeholders in programs put in place to handle vitamin D deficiency can use recommendations to come up with appropriate and practical solutions to achieve a vitamin D deficiency-free population

Developed countries need to evaluate vitamin D status in the population by measuring serum/plasma 25(O.H.) D. Public health intervention should be considered if more than 20% of the overall population records a low vitamin D concentration in the body. It should not fall below the standard vitamin D concentration in the body, 30 nmol/L. Once the vitamin D status has been established, the government, through its health department, can put measures in place to help the population evade vitamin deficiency. This action will help government agencies and relevant stakeholders to know the population affected by the deficiency, determine the resources required to facilitate their initiative, materialize it gradually and assure people of their health as far as vitamin D deficiency is concerned.

Furthermore, the government can include a mandatory or voluntary fortification in its national legislation. To materialize all the fortification initiatives, the government must identify the most fortifiable, widely consumed, and culturally acceptable vehicle. The most effective strategy to increase dietary intake of specific foods rich in vitamin D is fortifying government-mandated staple food in industrialized countries. The United States and Canada are already ahead with this initiative as they have mandated vitamin D through fortifying infant milk, evaporated milk, nonfat dry milk, and baby formula. This strategy will prevent children from developing rickets by providing enough calcium and phosphorus. The government should oversee the fortification of mandatory foods rich in vitamin D to ensure its safe levels and appropriate formulations in the respective foods.

The government should also devise a plan to use vitamin D supplements to ensure enough vitamin D consumption and decrease deficiencies and related illnesses. Sources of vitamin D supplements such as cod liver oil, which has the highest vitamin D content, should be maximized such that there is enough for all residents in developed nations. There is a need to employ new technologies and inventions to increase the production of supplements and control vitamin D deficiency. Stakeholders should also take the initiative and invest adequate resources in unraveling more forms of vitamin D such as capsules, drops, and tablets. Countries like the United States have already included various point-of-use multi nutrients fortification products such as lipid-based nutrients supplements, LNSs, and micro-nutrient power MNPs to counter vitamin Deficiency, especially among young children. The supplementation initiatives towards this course will improve vitamin D status, reducing vitamin D deficiency cases.

Advocacy

It is vital to create professional and public awareness regarding the risk factors and consequences of the deficiency to alleviate the disease burden that results from the prevalence of vitamin D deficiency in developed countries. There is a need for collaboration between local and international organizations to estimate the prevalence of vitamin D deficiency and strategize and implement effective and specific interventions to improve vitamin D status and acquisition in industrialized countries. Diverting attention to vitamin D deficiency, proper assessment, and monitoring the program’s effectiveness enable governments and stakeholders to determine if they are in the right direction and invest more in the most effective strategy.

Undoubtedly, vitamin D deficiency prevalence in developed countries is an issue that requires attention from different parties in the respective countries. Its evaluation should be based on recent statistics to represent the population accurately. This action will allow various programs that work hand in hand with the government to reduce the deficiency prevalence to channel resources towards the right course and achieve positive outcomes of vitamin D status. Incorporating vitamin D supplementation into childhood vaccination programs would be an effective strategy to implement and deal with the issue. Immunization campaigns and vitamin D supplements should be advocated simultaneously to create open-mindedness among parents. This action eliminates adherence challenges of frequent dosages of vitamin D among people, especially parents. Public members should also take it upon themselves and incorporate the habit of consuming foods rich in vitamin D and exposing themselves to the right amount of sunlight to get adequate vitamin D into their bodies.

Limited data on the prevalence of vitamin D deficiency in developed countries gives the government and relevant stakeholders the wrong impression. This is the case because factors that increase the risk of getting vitamin D deficiency are widespread across countries, making it challenging for the government to pinpoint and handle them separately to achieve effectiveness. Therefore, it is essential to conduct meaningful, in-depth research to generate accurate information about vitamin D concentration to determine its course.

References

Vitamin D and Bone Health

Vitamin D and Bone Health

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Vitamin D and Bone Health

Introduction

Vitamin D plays a vital role in the maintenance of healthy mineralized skeleton for vertebrates including human beings. Sunlight is normally behind the vitamin D3 photo-production in the skin. After its formation, vitamin D3 is sequentially metabolized in the kidney and liver to 1,25-dihydroxyvitamin D.1 The main function of the latter is keeping the concentration of serum calcium and phosphorus within a normal range to ensure the maintenance of vital cellular functions and the promotion of skeletal mineralization. Many foods lack vitamin D and those that are fortified with vitamin D contain variable amounts and humans cannot rely on them as he only source of vitamin D. Sunlight exposure provides humans and animals with the required Vitamin D. Deficiency and insufficiency of vitamin D has been recognized as the main cause of bone diseases among children and the elderly. The deficiency of vitamin D causes osteomalacia and exacerbates osteoporosis.1 Generally, studies conclude that an increased intake of calcium to 1000-1500 mg/d alongside a sufficient of vitamin D of not less than 400 IU/d is essential for the maintenance of good bone health. This paper will discuss the biochemical mechanism of vitamin D for bone health and the summary of published scientific evidence of the same.

Potential Mechanisms

Vitamin D plays the role of regulating the levels of blood calcium by enhancing calcium intestinal absorption and mitigating its elimination. In addition, it deposits calcium in the bone and removes it from bone in order to meet the needs of the body.2 The deficiency of vitamin D leads to a decreased calcium absorption and elevated parathyroid hormone (PTH) concentration. PTH is a hormone which increases the levels of calcium by releasing calcium from the bones. In the long run, the deficiency of vitamin D results in a bone mass loss that weakens the bone and leads to osteoporosis.1 Adequate intake of vitamin D leads to a decrease of bone loss be mitigating PTH secretion and prevents the excessive remodeling of bones (bone turnover).

Humans attain peak bone mass in their thirties with physical activities, genetics, lifestyle, and nutrition factors playing a major role in accumulating and maintaining their bones. Bone loss related to age is experienced when one is their forties leading to a slow decline of bone mineral density (BMD) although this process is augmented among females in their menopause owing to the likelihood of oestrogen deficiency causing bone loss.3 The bone disease development in later stages of life relates to humans attaining maximum peak bone mass and maintaining bone mass during adulthood. Studies show that insufficient intake of vitamin D over a long period of time results in demineralization of bones. Furthermore, the deficiency of vitamin D results in a decrease in the absorption of calcium and eventually the release of calcium from bone to maintain the concentration of calcium.3 A continuous turnover of bones and reabsorption tends to weaken the bone architecture and increases the risk of fractures through secondary hyperparathyroidism eventually resulting in osteoporosis and osteomalacia.

There exists a direct relation between bone mineral density (BMD) and risk of fracture with a decreased bone density and strength related to a high incidence fracture rate. Usually, fractures tend to take place on the spine, hip, and wrist. Fractures carry significant costs of health and leads to increase in mortality and decrease in life quality. Incidences of fractures increase with age; thus it is imperative for humans to establish preventive strategies so as to mitigate the development of such conditions.4 Given the relationship that exists between bone mineralization and vitamin D, optimal status of vitamin D is vital to minimize risk of fractures.

At any time, the vitamin D actions rely on both the status of vitamin D and dietary intake of calcium. When there is inadequate intake of dietary calcium and the status of vitamin D is deficient, it is demonstrated that there would be a development of osteomalacic bone with an increased lag time of mineralization.1 Under such conditions, there is an activation of phosphate homeostatic and plasma calcium mechanisms that include the system of endocrine vitamin D through plasma 1,25-dihydroxyvitamin D. The concentration of PTH can increase which elevates the CYP27B1 enzyme activity within the kidney to allow for 1,25-dihydroxyvitamin D concentrations although the concentrations of serum 25-hydroxyvitamin D might fall below 40 nmol/L.2 Under such conditions, there is a maintenance of intestinal phosphate and calcium absorption and there is a stimulation of osteoclastogenesis through 1,25-dihydroxyvitamin D and PTH interaction acting on osteoblasts to increase the reabsorption of bones. Moreover, there is the augmentation of bone cell activity which increases the number of osteoblasts multiplication and thus enhancing the RANKL expression to stimulate further osteoclastogenesis.2 When the concentrations of serum 25-hydroxyvitamin D is below 20 nmol/L, there is inadequate substrate for the renal CYP27B1 enzyme and the concentration of 1,25-dihydroxyvitamin D fall resulting in the fall of intestinal calcium absorption and osteomalacia and hypocalcemia development.

When there is a sufficient intake of dietary calcium but the status of vitamin D is low and vice versa, phosphate homeostasis and plasma calcium is maintained. Based on the serum 25-hydroxyvitamin D or dietary calcium concentration, the plasma calcium homeostatic mechanism may mitigate the concentrations of 1,25-dihydroxyvitamin D and serum PTH.2 But the RANKL expression in bone tissues is elevated with an increase in osteoclast surface and bone volumes and reabsorption are decreased. Mineralization lag times are then stabilized and the histology of bones demonstrates osteoporosis.

Summary of published scientific evidence to date

A study conducted by Veldurthy5 indicates that there are two actions that vitamin D exerts in order to modify bone health. Its findings show how vitamin D maintains phosphate homeostasis and plasma calcium preventing osteomalacia development. The authors states that the plasma 1,25-dihydroxyvitamin D contributes to the maintenance of plasma calcium homeostasis via an osteoblasts action in order to stimulate bone resorption and osteoclastogenesis enhancing the phosphate and calcium flow into the compartment of plasma.5 In addition, the authors assert that the serum 25-hydroxyvitamin D concertation is critical in order to ensure that sufficient of 1,25-dihydroxyvitamin D plasma concentrations is maintained and the absorption of intestinal calcium is 20 nmol/L. The other action by vitamin D is that it maintains the volume of mineralized bone tissue as assessed by the density of bone mineral and cortical and trabecular bone volumes. Therefore, it leads to the prevention osteoporosis development and reduction of risks of fracture.1 In this case, bone mineral density, bone histology, and increased risk of fracture, are all related to the concentration of serum 25-hydroxyvitamin D as opposed to serum 1,25-dihydroxyvitamin D.5 Dietary calcium intake and vitamin D interaction is possible since the most consistent data from randomized controlled trials for reduction of risk of fractures has been demonstrated when such nutrients combine.

Another review by Park et al. came to a conclusion that the greatest contributors to fractures are falls but the study also reports that the deficiency of vitamin D associates with weakness of the muscles and an increase in pre-disposition for falling.6 Such an association is not surprising given that this study shows that the expression of the VDR occurs in both myoblast cells and skeletal muscles. Evidence of the study demonstrates that vitamin D increases cellular growth and protein synthesis in muscle cells with increased number and size of type 2 muscle fibers which are vital as they are the first muscle fibers that are recruited when one falls.2 6 In support of this, an observational study by Burt et al. report that the plasma concentration of vitamin D in the 40-90nmol/L range is associated with more enhanced musculoskeletal function relative to serum concentrations <40nmol/L.6 7 In addition, the findings of the study suggest that reduced muscular functions in vitamin D deficient subjects could be available prior to the recognition of bone disease indications.7 8 Clearly, this evidence has provided a mechanism to support muscle strength improvement and in defacto bone health if vitamin D is supplemented.

Conclusion

Evidently, vitamin D is vital for bone health because inadequate intakes leads to diseases such as osteomalacia and enhanced fracture risk and increased bone metabolism. Research findings’ evidence to-date tends to indicate that vitamin D supplementation among those who are at a higher risk of impaired bone health has a favorable impact on the prevention of fractures. Many studies have shown that vitamin D improves BMD and enhances the function of the muscles as well resulting in a decrease in the number of falls. Vitamin D also can modulate the impact of pro-inflammatory cytokines on metabolism of bones. However, the required supplementation level is still under debate since various studies indicate different regiments of dosage. Many meta-analyses and trial have indicated that an 800 IU/d dose of vitamin D combined with adequate calcium intake is optimal. However, other studies have suggested greater benefits at higher intakes. There is a need for further studies to verify the optimum vitamin D dosage for better outcome.

References

1. Falchetti, A., Rossi, E., Cosso, R., Buffa, A., Corvaglia, S., & Malavolta, N. (2016). Vitamin D and Bone Health. Food and Nutrition Sciences, 7(11), 1033-1051.

2. Khammissa, R. A. G., Fourie, J., Motswaledi, M. H., Ballyram, R., Lemmer, J., & Feller, L. (2018). The biological activities of vitamin D and its receptor in relation to calcium and bone homeostasis, cancer, immune and cardiovascular systems, skin biology, and oral health. BioMed research international, 2018.

3. Hill, T. R., & Aspray, T. J. (2017). The role of vitamin D in maintaining bone health in older people. Therapeutic advances in musculoskeletal disease, 9(4), 89-95.

4. Dzik, K. P., & Kaczor, J. J. (2019). Mechanisms of vitamin D on skeletal muscle function: oxidative stress, energy metabolism and anabolic state. European journal of applied physiology, 119(4), 825-839.

5. Veldurthy, V., Wei, R., Oz, L., Dhawan, P., Jeon, Y. H., & Christakos, S. (2016). Vitamin D, calcium homeostasis and aging. Bone research, 4(1), 1-7.

6. Park, J. E., Pichiah, P. T., & Cha, Y. S. (2018). Vitamin D and metabolic diseases: growing roles of vitamin D. Journal of obesity & metabolic syndrome, 27(4), 223.

7. Burt, L. A., Billington, E. O., Rose, M. S., Raymond, D. A., Hanley, D. A., & Boyd, S. K. (2019). Effect of high-dose vitamin D supplementation on volumetric bone density and bone strength: a randomized clinical trial. Jama, 322(8), 736-745.

8. Fischer, V., Haffner-Luntzer, M., Amling, M., & Ignatius, A. (2018). Calcium and vitamin D in bone fracture healing and post-traumatic bone turnover. Eur Cell Mater, 35, 365-385.